first off I'd turn the camera on and examine the camera from the front to see whether there is any residue/fog/dirt etc on your lens or light sensor. If nothing is obvious then i would open the camera using thisguide and take a good look at all the parts for corrosion/mould etc. I think either your CCD connection has been effected by the humidity or their is condensation/mould on the light sensor (so that the camera thinks it's dark and is then overexposing your images) I would have thought that any condensation on the inner lens would have rendered images fuzzy/blurred/spotty, not over bright.